Several centuries have been taken toward the development of inventions made by different people into modern forms. Single inventors rarely bring out modern invention. What we have now as electronic devices (the computers) are inventions of several scientists, mathematicians and engineers from different centuries. For the purpose of this mini research key terms like evolution, technology and computer shall be considered, not forgetting to take a careful look at the evolution of these inventions from different centuries/years to our present generation starting from the earliest known device. The characteristics of these devices from generation to generation and their classification according to sizes, functions and uses shall also be discussed.
DEFINITION OF KEY TERMS
Evolution: Evolution is a gradual development that occurs in a particular place or thing.
Technology: This is the use of mechanical arts and applied science. Technology here refers to systems, methods of organization and techniques.
Computer:A computer is a programmable mechanical device that accepts information or inputs, stores and manipulates data and brings out the result or output in numerical format.
COMPONENTS OF A COMPUTER SYSTEM
A general purpose computer has four major components namely: arithmetic and logic unit (ALU), control unit, memory and input/output devices. These parts are interconnected by buses often made of groups of wires.
ARITHMETIC AND LOGIC UNIT (ALU)
This unit carries out arithmetic and logic operations. According to Stokes (2007), the set of arithmetic operations that a particular arithmetic and logic unit supports may be limited to adding and subtracting or might include multiplying or dividing functions ( sine, cosine, etc) and square roots. While others represent real numbers with the use of floating point, some can only operate on whole numbers (integers) albeit, with limited precision. Arithmetic operation could be carried out by any programmed computer. Logic operation can be useful both for creating complicated conditional statements and processing Boolean logic.
THE CONTROL UNIT
The control unit which is often called a control system or central controller, manages the computer’s various components. It reads and interprets (decodes) the program instructions, transforming them into a series of control signals which activate other parts of the computer. In order to improve performance, the control system in advanced computer may change the order of some instructions.
FUNCTION OF THE CONTROL SYSTEM
It reads the codes for the next instruction from the cell indicated by the program counters. It decodes the numerical code for the instruction into a set of commands or signals for each of the other systems. Whatever data the instruction requires from cells in memory are read by the control system. Necessary data to an arithmetic and logic unit or register is also provided by the control system. If the instruction requires an ALU or specialized hardware to complete, it instructs the hardware to perform the requested operation. It writes the results from the ALU back to a memory location or to a register or perhaps an output device. It could be observed that the sequence of operations gone through by the control unit to process an instruction is in itself like a short computer program.
The memory of a computer is seen as a list of cells into which numbers can be placed or read. Each cell has a numbered address and can store a single number. Anything such as numbers, letters can be represented by the information stored into the memory with equal ease. Software gives significance to what the memory sees as series of numbers. In almost all modern computers, each memory cell is set up to store binary numbers in gaps of 8bits or bytes. Each byte representing 256 different numbers (Stokes 2007). Several consecutive numbers may be used to store larger numbers.
Computer memory is...